SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69b5e7c1dd162f82374985a3f534616b999f67fc75bb540e633a12b24ca47697' 
  AND token = 'rSXW3dpB7DQBJuFXDCSVxyxLG2GTB2gqBpK+yBDDgeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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