SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e9f5b24e598ed5cea903d2dcedbe63ab2b11a0bfca7e3b2383efce0909f41d92' 
  AND token = 'ZO1OBVTIhQplAVNYvKkWm1/KSN99+fGZzwRh45S+1GA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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