SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2695f95e1d2cb81c7c21322e1de1f65f04a61ddfc77876fa144bef8f0e7cf85' 
  AND token = 'K1PN+/mj0hoYl9qvfIArjzCE5OmYFTAm/o8BYGnPfhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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