SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82d09fc9265a80e837252ea6666f92d98f0a56fe8e40c4989741234201de5b47' 
  AND token = '2GbBuMvPwqzs67RwFXVo4d8hjP3nlyL9i2tipYXaCiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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