SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9eac671a0ba59400a216b7e72659e0a125bc5e88546cbd08eee994cf05dafa2c' 
  AND token = 'FBENvAG/LYEcTI9mdCvPbL/sjUu+XUMtqacyYkF/PO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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