SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e6cfe13f75c8a03c8fb4c98d92bf61dd1dbd2d051a213363773f5be26b8957e' 
  AND token = 'rZWzWKnHtNUqgrI38Sd8Gn8ck0XYhZpnCqT4aKIqvIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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