SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f2caae1abbbaef7e17db0296b7c5e2256ec35c6a6f7e572db80355142febbdd' 
  AND token = 'lTYVxh/+2pCshmZ/jwPWgPPlNCMlIleb8hHSfWnJA9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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