SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85da69897be77e44dc4276582f57789cb90f7cf62ba8c362617354effda67b38' 
  AND token = 'TFZEJScL5Inx2kZtNaIJVsjvfx0zzKp78O58YVVh5GU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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