SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bd921884cb66656e3564dbf28b1f26b6fc25b6845eba60e34e3d73d3d659924' 
  AND token = 'JAlmcShuMPmU96GWI2S5F4zqCgB+JkSKzCByzbzWUoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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