SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '205e38f4f5c86285103bf8e0c5133c3a53f9dbb003f08cb74b119c305def7e19' 
  AND token = 'pTLemvOaOseOsduhNwXpvXLrlzDTxni0G0kc9ThaEDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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