SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fef0ae7d83ec2cbe9e5aa40232c72071463f6fd1fb83604aaa0f96831f888405' 
  AND token = 'COzjXAyCxp+AhlFJDmkTu03E0TcnRm3fwk1u9Zn5nBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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