SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd6d6dda3f2895384bb15a7be5bbd8535b64b470eeb891d614e9aa869c0cd43e' 
  AND token = 'EMSGwYBWevLTjUaBs+zpuHZXlOskI0I/MJuSYBTziKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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