SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebf7e93a72ea2683c5a34d95ec7bd870aa10d281168281f271ac1537d494d166' 
  AND token = 'XfV3WGo5uMFixBPmRZC0+/NbGRBRuJuC7MPSMaHzAXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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