SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b73ffdcc0515a260215902a6a446f85467c667b93d06365c96a2388d9f4a491d' 
  AND token = 'O4wquV5b+8FT1fAdzcoBuaFWeieyQHHbqX6ljkLRsYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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