SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52982e4cc5d1be95688199e88a67025473cd7911be30800cb8d5238227276834' 
  AND token = 'kreRr0xTgdLvbJyDPa+3Fq9vNKo7TJjqLzoDtwjogtg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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