SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd83fbfc97bf2b99bd10454133940974ffdc89b6083f613918c2c7b4a0e520be0' 
  AND token = 'bdhpxcJPtUbK64cgMaH3Mkq4cIG3IA4GhC8PflYR/F0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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