SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ff428738780a6119b0bf0b4489938ce0b4f66e835546b6ba7d37073ff1cb6fd' 
  AND token = 'rYcImz0rCTqSA7N7ax62ydL1Oei8H/MXqAKUDPzY1SY=' 
  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"
    }
  }
}