SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55f9f129cc89467e8b9c27bce9a470c4932602909b5f9e3f856e7b876e2dff63' 
  AND token = '2gGOFFYgUbplh13rA1MOshIqnubPrZt9vwiIaBVok2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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