SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '069c9e6d014f7954903b987de1cc1d889087c0e2d5b30c62324c989d14e5770f' 
  AND token = 'nCUCPXT305r2HgvIheXTrROwavC2lpwS78wSwN5NfOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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