SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd3c5a057bdea8c3ee394cfede661906dbba4afb6c952658f3d30f0d8a58eebb' 
  AND token = 'ncbRd+6hcL9nVB8nAUzG8ZUDGJYx9iUATZeXKtnAaNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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