SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c034e1111133e44c27fa9afb6a801f0b8d599824d35d83db75a5e5141c6c9607' 
  AND token = 'TsZPCqWXPYvMnHJbtkW3xGrXQP3htlAJahuXPQGLqYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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