SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f5be472710cc2b0ebc36b4b5125a8cbad6c35f47cf3af3de39d488ca2f47aca' 
  AND token = 'qP4w2HJ5qRJ39vm5GEGA7Qop1kqj84ivQExIWiMBzWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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