SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64d93a72ea8b2969efb88ca8c8099996ff986740e7dea06b46289e726c9519f1' 
  AND token = 'gFYjjQgL7hgzrWIWfQR13ClAa9u1eJNsSZHUa0Z+Y2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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