SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d1f9a07d2eaacf4b98ad6f45ccfb47b98d86423f351c88e7f2745926bb41a9e' 
  AND token = 'cYOaTlhlNmDijuLqJ2EgSEITSS26+KWKgr6T7hKBXS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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