SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d66f7c881d8fe22797efadf26ac0045ba8fff78f933befe07f6ad455077d7d6' 
  AND token = 'fDAotSMzcvsPBncfx9GSUBgY89xJ1kVh+Lx85WyPVHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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