SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '943f578900c863487b8399ddc87c95b76e8860e8280dea28a95775f61676807c' 
  AND token = '/TWNyFmfD8kOS9l1awGKYcpH2CUwUlSgKnZiDkPC5dQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}