SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a82c010e735789a19796c6a7e443694af40a7a4acaca99861a78c7fe76820fc' 
  AND token = 'iXAJYycbFcDWeVYCYtfZPL2bnBzER6JM2RsoPXiCACk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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