SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c291dcd0a6c4466aa4d6f2501747bbfa1e38f7322e8a29e29078c761cfab7945' 
  AND token = '5UigdflfNtpPO+swgpgt+QgB6lKxNX9XLhAVJjCWv80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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