SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e34509c89f458a1d4e4df063bab7c4d342c3fba21a1727ff439a95ca045e751' 
  AND token = '0Z7t8bxIkbp7i2k8eL1SLG3D9PGnAO7Wm+i6mAV99FA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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