SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f01225104b5e285988c30635ddcd22a666fe72692bbacb3d406cdc4bd10f821' 
  AND token = 'wfPf/uJFfxw+FsiPFi2F7OLL8cFhOka3QxPlEAZyDTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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