SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84eaf176f0055b3e3372f0d1dbf5fd5672cce06d9674a6272ef084fd49e49089' 
  AND token = 'vxAhDiJIcqLQQM5L3DJNKVUXjpBP82l4Ww2DgySvxyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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