SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3308e6291982f2ab82191d5ad57e4239e6701959a3c46ea1e4d9de0eb8fcf4e5' 
  AND token = '3WredUvlpD/bKNnKa+PqFX1CYfofeVdTuKXMyOAuewE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}