SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bde3caf321237c509d098f064938a5069c38a78fb6cd70460d994892282059ad' 
  AND token = 'sTU5YDPN6i7NzEuOixF+2DhAQHfRQw2RQNBEz5mC1FQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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