SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6e2d692df9054acbd4fc22e7a6193ba9f93ff457f926a501701307d85e4d130' 
  AND token = 'KJt2p3P/VX3Q2Gu+5FL5afW2FLnH2umqZjqIBOu3l9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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