SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9e4b7d1c1af843f274c372bb4a45a7736889365c838d553fd02dc95ed59bf36' 
  AND token = 'ToN4C71kJa4VNZLRtPaVB+4R14FvDX7vyafcoKPfes4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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