SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c58bb7422139564c6a3c13700fe8968adfe5dfa46d65b38bd7d68804bc6dc033' 
  AND token = 'FeIAChpZJWBR9FwAsjIHiUFbCv1W67APc+ncKYauBRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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