SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd09cebc81ebe25bb85db809fc3a1e89dad724505fd7988b42362ab15943ff830' 
  AND token = 'ifXGCLb/8NaR7Bdv/EDlsD46h0Nfgc+Y1HYMM4NJOqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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