SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75df12571e15283d317242a1b22ce5c62e4c0ceb85a0949f96c3a73336eccd36' 
  AND token = 'YjJ6Zwn46zB/l44La7Ge5l+bQsRGPAFtQlsUC6Emoq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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