SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '025932914f8124f9dcc22736df6bedbb028ea975ba5551320da1ebad97b6a938' 
  AND token = 'RG1sevqInpGVRUUiySSzKQS7+7CL8hJtvYtMEmEk+iA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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