SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2c549cce48bc32fb3adc4dcb95a5c96effe1800f0c37afcfcff6fd81ae53063' 
  AND token = 'qniou7XYMlP+9i4tt/5gg1FV8FcsHEKHgrywliLV+qE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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