SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bc193b297846ec4c0cd8859a7097104640d08cb43fd6dc232876de7241778e1' 
  AND token = 'OkrfBgJDbWw5/CLSAe2fZWKOZFaSLS8tYVmWqcGVuIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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