SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdb4471319ca7a0896d447ada2b447a383108d29fb9ac399eae45ec1dc5ae958' 
  AND token = '6GbEtV7zCWSUml1kO1yFPv4oAeuDswdD0LeYEapOjoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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