SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfbf7cc9c9e3a8cba59f66ac1bd63bd28e4599cbb023b7995dc86cfbd2099f85' 
  AND token = 'PS5bipNZDjonsnblIXPvn7iCCXIqh85dCc9hIrSCIY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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