SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f0833e8ea460dbce84f41f860b1a9c0869a8d77fe99b162d2471557de0ace943' 
  AND token = 'Pd1nRS0e0+FtDtdhLfx47JSwJELF4pAR+uTPG7wwAOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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