SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84a45125a066f11241c98a55fb32939b311bac43c4a3a22eb7532582cd9296b6' 
  AND token = '5BcEqXWDoDfmYBYwsG5nvNIJF7H+t7oW7wqhVb6Pl2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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