SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df055ed719cdcf1173dd5e407a5f03e30c1c52cf63ef820f10201165f7c9c181' 
  AND token = 'oUDSEoTxKmLm13AnGB4RoPD8PfYtXeZKySac5cWseiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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