SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a2af514dd89016259581d4d92d21bb9753fb3580e357a187b738847809c2cce' 
  AND token = 'T7oaSnvh//ctiXOd1lB50H00ekvtyCSN9pmaaWPCNC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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