SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08e5c1b9193511a436ef3458617fd03bf52ecbb0d5c353a419b2d11e677fa722' 
  AND token = 'obD7K1g3hRThJbKdUS5pmoulr+EGKdZxfs/c5wAGJvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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