SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6c61dc0434ec57b9a100229721a6348f602a2046d53c7fc22238eede7b8bd594' 
  AND token = '0pCvAWrQICA9qP79/R702m9FwpnhquFOsV/gmUBMm4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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