SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '40f8ee87c3ba5e7bcd7f538db716c1f44134f05e359f1758fee52b7c04d52091' 
  AND token = 'z7HyLFcXdNA+cPUQZaIoL6G2EZIZN1UBy/YuKTSoVPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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