SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05deb21cfaf23a47952de69d052ead990abb1c5d01eddb15a35ebdb6f16f740e' 
  AND token = 'Im/16LMWXbDA0XsZtooiKBel5kpYHuezkqHQTcoMMFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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