SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2a6a167c0ab457acdbed39de66654de57e96e2028162006ee12067595582f90' 
  AND token = 'CZNeRVH5GuiyMQ5L0bhb06y5GrUVsZEn9ci6Ml/xWPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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