SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be161761fb01b87282d5a2019933646203d8e44a448cdf43bc490dc4feb826e1' 
  AND token = 'mHAemdH8Oe9RN62hm31+h4GhRsrs/NQbC6NIySDgg+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}