SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9422861fa2ddbe9ca8471fcd97e6f7060481f6d90e0e38829664b9f10e4ce939' 
  AND token = '4CM1r+I7ecQBS7HdJX2OY9VgxKoK7IRx8xN9At/tuag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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