SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68c3457a48a2d08175889bcf9899a069126a7c0e4b5b120b6a94ef913d853906' 
  AND token = 'HgpiN1HkF2gg3E+e61nRDlDqNVQacPioLvhPfJxaIHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}