SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '658f97cfe9468e4336393cc8e5f6564f4da9b149020131268a47766936c8ff87' 
  AND token = 'YfbPuHAl+t5pFlMhiFJUlSBMVBS3xohtCKCI1z1owDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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