SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d6cf41c58277fa94d1d3fecff655b98af722b84c85e4bec328dfcbe7c844a25' 
  AND token = 'uudzoUyt2j7PNGGvkT09jbsmR2EYc/vbhqfsUKRBFrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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