SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '656aec85e9bcc5a04cf396b1c4aa61011e7db6f44fbb51702a5294b0a81add64' 
  AND token = 'Y47UjxGau87KYfiHbn24vz+hUkWFU+MUnJ0xgBj/qDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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