SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe93f3790ba057d9d21c56cff528e0ebe7f62fbb20f438b6bd003740473b16c2' 
  AND token = 'qNY+hBoEkPT0cKNsZwlSsuAKvfU05R6gwxefeRsBYOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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