SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c4a86f9897bcd0ebe8e78a2c70e9f235a4abfcea00aed3b216364cb212017811' 
  AND token = 'YBY8nBkrnzOScp1VT2Hw3xbPtFi1yyBhtWSlSaOlfl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}