SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c83f3c483ab71822611cd116c6fbb25d1d2965a60857cbd46ed657b27061f9ff' 
  AND token = 'F6lFgDMUjQVLgiwJojuOB43mOIIGf7oF+CbpMdBlERE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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