SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6181066221635d6d7844b2245070069ea0c47d4d3b4f7eb1e1c61b3c151e40ed' 
  AND token = 'zXk+Uf2aWEeGVwvNWlOBnZ4sjPFPdWTKvydKuMGLiUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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