SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e467974bb6a04ac2e4dfaaa93fd408dbb0e460842e11b528c3f98282667118e' 
  AND token = 'hBLsgEBmaMXVIZW4Wdl+tMgTAkVCQAj3xKNrAhxyxok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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