SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e7b1c061dbf4ab64b76a5671eda394f4cb65ccd815573016f86016b263870dcc' 
  AND token = 'NL8Sk8UC1FIVkl+SkzDzfr4j6jVu/sM4ZVSp5x9PnEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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