SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaff97328b8995550db36a7cff90901024d3d4c5db95dbf75737613f4c495416' 
  AND token = 'evTwxieV78LNyyUMeXxpl3w//b8h3ct1+FbGLqGO7bw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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