SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '241350b918615e77e9d0eac95a185b8e9c4bc64123f6f1d19f47f174441a2467' 
  AND token = '/mWLHoIHMzPs45O0vlr4sbeCDcQScHMJVmn6bJYM5pU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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