SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65a64192b9d5171534ffef65b10d2d878d3c1c329e5d04424b524fca7ec474c9' 
  AND token = 'Vz1VwBOKIft9zP0tk+B5REmvrIxX6nqutYmCsq/SV7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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