SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc0fb6839fa38f5221a998bd6ea5af15cffdbdd37ae568de36e70c008848770e' 
  AND token = 'gKBJOoTC691Z+z7DPB+uozwcjXMDQiyllOdFbvhFcl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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