SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd4b5a1dbd455ecb4c242e6cb89ebc1b73d2793fc0335d5e1fb31172d344a5932' 
  AND token = 'mX/av9OSTCFTkL/ghjPX0KUstx12V0KhgfHx2UCPQCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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