SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18f6184410c4d40aac655e96dce47945e21e2c2be918b067948b6f1dacf07601' 
  AND token = 'MBceaU0r9Yah5hcD24gTkZ3P5nTR/31KkaQZYreW/x0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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